NAME
Perl::MinimumVersion - Find a minimum required version of perl for Perl
code
SYNOPSIS
# Create the version checking object
$object = Perl::MinimumVersion->new( $filename );
$object = Perl::MinimumVersion->new( \$source );
$object = Perl::MinimumVersion->new( $ppi_document );
# Find the minimum version
$version = $object->minimum_version;
DESCRIPTION
"Perl::MinimumVersion" takes Perl source code and calculates the minimum
version of perl required to be able to run it. Because it is based on
PPI, it can do this without having to actually load the code.
Currently it tests both the syntax of your code, and the use of explicit
version dependencies such as "require 5.005".
Future plans are to also add support for tracing module dependencies.
Using "Perl::MinimumVersion" is dead simple, the synopsis pretty much
covers it.
METHODS
new
# Create the version checking object
$object = Perl::MinimumVersion->new( $filename );
$object = Perl::MinimumVersion->new( \$source );
$object = Perl::MinimumVersion->new( $ppi_document );
The "new" constructor creates a new version checking object for a
PPI::Document. You can also provide the document to be read as a file
name, or as a "SCALAR" reference containing the code.
Returns a new "Perl::MinimumVersion" object, or "undef" on error.
Document
The "Document" accessor can be used to get the PPI::Document object back
out of the version checker.
minimum_version
The "minimum_version" method is the primary method for finding the
minimum perl version required based on "all" factors in the document.
At the present time, this is just syntax and explicit version checks, as
Perl::Depends is not yet completed.
Returns a version object, or "undef" on error.
minimum_explicit_version
The "minimum_explicit_version" method checks through Perl code for the
use of explicit version dependencies such as.
use 5.006;
require 5.005_03;
Although there is almost always only one of these in a file, if more
than one are found, the highest version dependency will be returned.
Returns a version object, false if no dependencies could be found, or
"undef" on error.
minimum_syntax_version $limit
The "minimum_syntax_version" method will explicitly test only the
Document's syntax to determine it's minimum version, to the extent that
this is possible.
It takes an optional parameter of a version object defining the the
lowest known current value. For example, if it is already known that it
must be 5.006 or higher, then you can provide a param of qv(5.006) and
the method will not run any of the tests below this version. This should
provide dramatic speed improvements for large and/or complex documents.
The limitations of parsing Perl mean that this method may provide
artifically low results, but should not artificially high results.
For example, if "minimum_syntax_version" returned 5.006, you can be
confident it will not run on anything lower, although there is a chance
that during actual execution it may use some untestable feature that
creates a dependency on a higher version.
Returns a version object, false if no dependencies could be found, or
"undef" on error.
minimum_external_version
WARNING: This method has not been implemented. Any attempted use will
throw an exception
The "minimum_external_version" examines code for dependencies on other
external files, and recursively traverses the dependency tree applying
the same tests to those files as it does to the original.
Returns a "version" object, false if no dependencies could be found, or
"undef" on error.
version_markers
This method returns a list of pairs in the form:
($version, \@markers)
Each pair represents all the markers that could be found indicating that
the version was the minimum needed version. @markers is an array of
strings. Currently, these strings are not as clear as they might be, but
this may be changed in the future. In other words: don't rely on them as
specific identifiers.
BUGS
Perl::MinimumVersion does a reasonable job of catching the best-known
explicit version dependencies.
However it is exceedingly easy to add a new syntax check, so if you find
something this is missing, copy and paste one of the existing 5 line
checking functions, modify it to find what you want, and report it to
rt.cpan.org, along with the version needed.
I don't even need an entire diff... just the function and version.
TO DO
Write lots more version checkers
- Perl 5.10 operators and language structures
- Three-argument open
Write the explicit version checker
Write the recursive module descend stuff
Check for more 5.12 features (currently only detecting "package NAME
VERSION;", "...", and "use feature ':5.12'")
SUPPORT
All bugs should be filed via the CPAN bug tracker at
For other issues, or commercial enhancement or support, contact the
author.
AUTHORS
Adam Kennedy
SEE ALSO
, PPI, version
COPYRIGHT
Copyright 2005 - 2013 Adam Kennedy.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
The full text of the license can be found in the LICENSE file included
with this module.